Motor-controller.



' C. W. YERGER.

MOTOR CONTROLLER.

APPLICATION FILED OCT-28,1913.

51,225,096. Patented May 8,1917.

III M m 12 13%] 10 UNITED STATES PATENT OFFICE.

CHARLES W. YERGER, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE CUTLER- HLAMMER MFG. 00., 0F MILWAUKEE, WISCONSIN, A CORPORATION OF WIS- consm. I

MOTOR-CONTROLLER.

Specification of Letters Patent.

Patented May 8, 1917.

To all whom it may concern:

Be it known that I, CHARLES W. YERGER, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Motor-Controllers, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a art of this specification.

- y invention relates to improvements in motor controllers.

It may be advantageously used in various different relations and particularly in connection with electric elevators.

In elevator service it is highly desirable to provide for gradual and smooth acceleration and deceleration but much difliculty has been experienced in this connection. For example, the back lash or lost motion in the gearing, the wide variations in load and the establishment of dynamicbrakin connections have all given much trouble 1n this connection.

My invention has among its objects to provide a controller for the aforesaid and other classes of machinery where the foregoing or similar conditions are met with which will rovide for much smoother acceleration and eceleration than has heretofore been attained. 1

Various other objects and advantages will hereinafter appear.

For the purpose of more fully disclosing the nature and advantages of my invention, I have illustrated in the accompanying drawing a very simple embodiment thereof which I shall now describe.

The controller is shown as applied to a" accelerating switches 3, 4 and 5 and an electro-responsive armature shunt switch 6 which normally stands in closed position. The switches 3, 4 and 5 control resistances r, 1- and 1' in series with the motor, and are governed by series relay switches 7 8 and 9 respectively. The armature shunt controlled b the switch 6 includes a resistance r. 'l he operating windings of the switches 2,

3, 4, 5 and 6 are controlled by a master switch 10 and certain interlocking contacts hereinafter specified.

Briefly set forth, the controller functions as follows:

It starts the motor with both the series resistances 1', r and r and the armature shunt resistance r included in circuit. The armature shunt resistance is manually controlled and may be left in circuit as long as desired but must be disconnected before the switches 3, 4 and 5 can respond. Further, as will hereinafter appear, provision is made where by the armature shunt is necessarily maintained for a temporary period after starting. When the switch 6 responds to open the armature shunt then the switches 3, 4 and 5 respond automatically and successively to accelerate the motor, subject to retardation by the series relay switches For deceleration the resistance r is first connected across the motor armature by the switch 6 after which the switches 3, 4 and 5 are denergized successively to reinsert the series resistance. Thereafter, the main line switch '2 isopened to disconnect the motor from circuit *leaving the shunt around the armature whereby the motor acts as a dynamic brake. Thus provision is'made for shunting the motor armature through the resistance r for starting and for insuring interruption of the armature shunt prior to removal of any of the series resistance, whereas in stopping the resistance r is connected in shunt with the motor armature before any of the series resistance is reinserted in circuit. I

The inclusion of the shunt resistance r in starting insures initial speed and torque of a very low value whereby any back lash or lost motion in the gearings may be readily taken up without shock or jar to the driven machinery. Also, the shunt resistance per forms another very important function, especially in connection with controllers governed by the speed or electrical conditions of the motor, in that it compensates for variations in load to prevent undulyabrupt acceleration. As is well understood, such types of controllers are adjusted for maxi- I mum load starting whereby if the load is light there is a tendency for an exceedingly abrupt acceleration. This, however, is prevented by the shunt resistance which insures low speed and low torque for at least a temporary period, irrespective of the load conditions and accordingly insures a gradual and smooth initial start. On the other hand, the armature shunt in no wise interferes with the operation of the controller under heavy loads since if the motor fails to start said shunt may be'interrupted after a short interval by operation troller.

Reverting now to the-deceleration operation, it will be observed that inasmuch as the resistance r is connected in shunt with the motor armature while all of the series resistance is excluded it will have absolutely no efiect on the speed. of the motor. How ever upon the reinsertion of the series resistance it aids materially slowing down. the motor and in producin a uniform deceleration. Thus the ditfi ulties heretofore met with in the establishment of an armature shunt for gradual slow down are entirely eliminated and the shunt tried to great advantage in deceleration.

The controller and its circuit connections will now be more specifically described. The master switch is provided with contact fingers 11, 12 and 13 and with electrically connected coiiperating segments 11, 12 and. 13% In its first operative position it bridges contacts 11 and 12 by segments ll 12 and in its second position bridges contacts 11 and 13 by segments 11. and 13 in its first position a master switch closes circuit from line L by conductor 1% through the Winding of switch 2 by conductor 15 to contact i2 and thence to finger 11 by conductor 18 to line Li Switch 2 thereupon responds to complete the motor circuit.

The motor circuit may .L from line L through J through the operc'ti it) 7, by conductor A) of the master 0011- open the resistance shunt around the motor armature. In this connection, it should be noted that switch 6 cannot respond until switch 2 closes and until the master switch is thrown to full on position. Accordingly, a time element is provided whereby the retention of the shunt is insured for at by the relay 7 and upon responding varies the motor connection. The motor circuit then extends from conductor 19 by conductor 83 through switch 3, by conductor 3 through the operatin winding of relay 8 by conductor 36 to an through resistance 9 etc. Switch 3 upon responding also comp'letes, through auxiliary contacts 3, the" circuit of the winding of switch 4. This circuit extends from conductor 33 through said auxiliary contacts, by conductor 37 through relay switch 8 and thence through the winding of switch 4 by conductor 38 to conductor 32. I

Switch i thereupon responds subject to retardation by relay 8. The motor circuit then. extends from conductor 3& by conductor 39 through. said switch 4, by conductor 40 through the winding of relay 9, by conductor ii to and through. resistance 5 etc. Switch 4; upon closing also completes a circuit from conductorBS through its auxs L"; by conducto through gh. the op- I, by conductor lding. ward.

What I claim as new and desire to secure by Letters Patent is:

1. In a motor controller, in combination, means for establishing power connections, accelerating means, means to normally shunt the motor armature and means necessitating operation of the first means to 'establish power connections prior to operation of the third means to interrupt the armature shunt and necessitating such operation of said shunting means prior to operation of said accelerating means.

2. In a motor controller, in combination, means for establishing power connections, automatic accelerating means, means to normally shunt the motor armature and to control said accelerating means to insure against operation thereof pending interruption of the armature shunt and means in su'ring retention of said armature shunting means in normal position during establishment of power connections and for a temporary period thereafter.

3. In a motor controller, in combination, means for establishing power connections, means to normally shunt the motor armature, automatic accelerating means dependent for operation upon prior operation of said second means to interrupt the armature shunt and manual control means for said first two mentioned means insuring maintenance of the armature shunt during establishmentofpower connections and for a temporary period thereafter variable at will.

4. In a motor controller, the combination with electro-responsive means for establishing power connections and increasing the power supply for accelerating the motor, of electro-responsive means normally completing an armature shunt and control connections for both of said means insuring retention of the armature shunt forsa temporary period following establishment of power connections and necessitating interruption of the armature shunt prior to any increase in the power supply.

5. In a motor controller, the combination with electro-responsive means for establishing power connections for themotor and increasing the supply of power subject to the electrical conditions in the motor circuit, of means normally completing a shunt around the motor armature and insuring against response of said first mentioned means toincrease the power supply until after interruption of the armature shunt.-

6. In a motor controller, in combination, means for controlling the continuity of the motor circuit, means for completing an armature shunt for the motor upon initial closure of the motor circuit and a series relay power controller for accelerating the motor but only after previous operation of said second mentioned means to interrupt the armature shunt.

7. Inca motor controller, the combination with electro-responsive means controlling a shunt for the motor armature, of electroresponsive means for controlling the power supplied to the motor, and means for directing the operation of said former means to slow down the motor, said first mentioned means operating to complete the armature shunt prior to any reduction in the power supplied to the motor.

8. In a controller for electric motors, in combination, means controlling the power connections for the motor and varying the power supplied for both acceleration and deceleration, of means normally completing a shunt for the motor armature and acting to interrupt said shunt prior to any increase in power for acceleration and to reestablish said shunt prior to any decrease in power for deceleration.

9. The method of controlling an electric motor with an armature shunt resistance, and a series resistance consisting in starting with both resistances connected in circuit, progressively, interrupting the armature shunt and gradually excluding the series resistance for acceleration and progressivel reestablishing the armature shunt and grad ually including the series resistance for deceleration.

10. The method of decelerating an electric motor consisting in first shunting the motor armature with all series resistance excluded from the armature circuit to minimize the effect of the shunt and second inserting re- 100 sistance in the armature circuit while maintaining power connections to increase the slow-down effect of the armature shunt.

11. The method of decelerating an electric motor consisting in shunting its armature 105 with all series resistance excluded from the armature circuit to initially minimize the effect of the shunt and in thereafter inserting resistance in series with the motor armature while maintaining power connec- 110 tions and a constant value of the armature shunt to thereby increase the slow-down, effect of said shunt.

In witness whereof, I have hereunto subscribed my name in the presence of two wit- 115 nesses. CHARLES W. YERGER? Witnesses: P

F. H. HUBBARD, S. F. WATSON. 

